Features of viral meningitis
Epidemiology, pathogenesis, clinical features, diagnostic approach, and differential diagnosis of viral meningitis.
|Epidemiology||Enterovirus: MCC, immunocompetent, hypogammaglobulinemia|
Arbovirus: immunocompetent, blood donors, organ transplant (WNV)
LCM: mice/hamster owners/handlers
EBV: oral secretions, allogeneic bone marrow transplant
|Pathogenesis||Enterovirus: fecal–oral contamination → replication in intestinal lining → viremia and seeding of CNS. Clearance by antibody mechanism|
Arbovirus: mosquito/tick bite → local replication in tissues and lymph nodes → viremia and seeding of CNS
HSV: inoculation during time of genital infection → latent infection in sacral DRG → reactivation of genital lesions, radiculitis, and meningitis
|Clinical features||Fever, frontal/retro-orbital headache, pain on extraocular movements, photophobia, neck stiffness, maculopapular erythematous rash from face to trunk. Focal deficits and seizure not seen|
|Diagnosis, CSF studies||Lymphocytic pleocytosis, normal-mildly decreased (enterovirus, HSV-2, VZV) glucose, normal-mildly increased protein|
Enterovirus: RT-PCR, throat/stool culture (presumptive diagnosis)
Arbovirus: antibody titer in serum, IgM antibody in CSF
PCR: WNV, HSV, EBV, HIV
|Differential diagnosis||Fungal (MCC: cryptococcal), Mycobacterium tuberculosis , and Lyme disease|
DRG , Dorsal root ganglion; WNV , West Nile virus; LCM , lymphocytic choriomeningitis; MCC , most common cause; EBV , Epstein–Barr virus; CNS , central nervous system; HSV , herpes simplex virus; VZV , varicella zoster virus; RT-PCR , reverse transcription polymerase chain reaction; CSF , cerebrospinal fluid; HIV , human immunodeficiency virus.